/**
 * This file is Copyright © 2008 Software Craftsmen Limited. All Rights Reserved.
 */
package com.softwarecraftsmen.collections;

import org.jetbrains.annotations.NotNull;
import com.softwarecraftsmen.functors.Boolean;

public interface Collection<K> extends Mutable, OrderingAndSorting
{
	@NotNull
	Boolean isEmpty();

	@NotNull
	Boolean hasElements();

	int size();

	@NotNull
	com.softwarecraftsmen.functors.Boolean contains(final @NotNull K key);

	@NotNull
	Boolean doesNotContain(final @NotNull K key);

}
